The document contains footnotes with links to a number of articles and other sources on the internet, but a number of sources seemed to not lead to valid websites.

Rolf Frøysa, the chief technology officer of a Norwegian broadband firm, began to investigate. He's launched a Wiki that keeps track of his findings.

Worryingly, when Frøysa looked dug into the codes, he found that they appeared to be coordinates. He wrote, "when plotted on a map in the most obvious way, these coordinates/points correspond with major European cities".

Here's the map of the coordinates:

The Telegraph notes that much of Breivik's manifesto was plagiarized from the Unabomber, Ted Kaczynski, who left a number of his own codes in his own manifesto.

”It could just be a hoax or part of his [Breivik’s] PR strategy,” Frøysa told the Telegraph, ”but we need to investigate this document.”